Year code T which is 64. Has Diamond shape ID Plate. What I can find is 63-64 were pre Air flow. This 1 has an Airflow grill and lights. How easy is the swap? Just the grill or the whole front panel? Also a model 119E which Right hand drive so must have been changed over at some time.

(T) month code for December. 119E (LHD) 118E (RHD) with 1500cc.
It's common to swap the grille and parking lights. A true airflow has the pillar vent screen as the pre-airflow has the opening rear window.
Diamond I.D. were '62-'64 models. '65-'66 are rectangular.

That is a misprint. 119E LHD. 125E designation for Lotus Cortina MK1. Pre-airflow are RHD. Air-flow models were produced LHD and RHD. There is some debate whether Lotus made any LHD pre-airflow models.